• Title/Summary/Keyword: Acetylenic

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Phytochemical Constitutes of Artemisia japonica ssp. littoricola

  • Kwon, Hak-Cheol;Lee, Kang-Ro
    • Archives of Pharmacal Research
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    • v.24 no.3
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    • pp.194-197
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    • 2001
  • The phytochemical study of the aerial parts of Artemisia japonica ssp. littoricola (Asteraceae) led to the isolation of two acetylenic compounds, (3R)-dehydrofalcarinol (2) and (3R)-dehydrofalcarindiol (6), two sesquiterpenes, $1{\beta}$, $6{\alpha}$-dihydroxy-4(15)-eudesmene (5) and oplodiol (8), and four phenolic compounds, eugenol (1), vanillin (3), 3'-methoxy-4'- hydroxy-trrans-cinnamaldehyde (4) and p-hydroxyacetophenone (7). Their structures were determined by chemical and spectroscopic methods.

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Comparison of Stereoselectivity in the Reactions of Crotylmetal Reagents with Dicobalt Hexacarbonyl-Complexed and Uncomplexed Propynals

  • 박상규;김석인;조인호
    • Bulletin of the Korean Chemical Society
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    • v.16 no.1
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    • pp.12-16
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    • 1995
  • The diastereoselectivity of addition reaction of crotylmetal reagents to cobalt-complexed acetylenic aldehydes and metal-free aldehydes was examined. The anti-diastereomer was the predominant product when the crotyl metallics were Cr, Sn, and Zr. In THF, the uncomplexed aldehydes normally gave higher anti-diastereoselectivity. However, the cobalt-complex of silicon-substituted propynals with three bulky substituents produced increased proportions of syn-diastereomer. In DMF, the selectivity shifted towards syn-isomer except in the case of dimethylphenylsilyl substituent. When tributylstannane was used in the presence of BF3 etherate, moderate syn- selectivity was observed with uncomplexed aldehydes, but only decomposed products from complexed aldehydes.

Photooxidation of a Polyacetylene Compound from Panax Ginseng C.A. Meyer

  • Koh, Hun-Yeong;Chang, Suk-Ku;Shim, Sang-Chul;Moon, Soon-Ku;Min, Tae-Jin
    • Bulletin of the Korean Chemical Society
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    • v.7 no.3
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    • pp.179-182
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    • 1986
  • A major polyacetylene compound from Panax ginseng roots, heptadeca-1-en-4,6-diyn-3,9,10-triol, was irradiated with 300 nm UV light to obtain a photooxidized acetylenic compound having the conjugated en-on-diyne chromophore, heptadeca-1-en-4,6-diyn-9,10-diol-3-one. The same oxidation product was obtained exclusively by 4-(dimethylamino) pyridinium chlorochromate at room temperature.

Electorchemical Reduction Behavior of Aliphatic Acetylenic Alcohol (Aliphatic Acetylenic Alcohol의 電極反應過程)

  • Kim Won Taik;Kim, Jin Il;Kwak Tai-Young;Lee Ju-Seong
    • Journal of the Korean Chemical Society
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    • v.23 no.3
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    • pp.180-185
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    • 1979
  • Electrochemical reduction behavior from 2-butyne-1, 4-diol (BID) to 2-butene-1,4-diol (BED) by the use of various cathodes, such as Ti, Zr, Ni, Pt, Cu, Ag, Au, Zn, Hg, Pb and graphite has been studied. It has been found that cathodic polarization curve with metal of IB subgroup such as Cu, Ag and Au consisted of one wave in BID-alkaline solution, whereas it was not formed any wave in BED solution. Therefore, it was found that the cathode which was the most suitable in order to proceed in this reaction was Cu, Ag and Au. At cyclic voltammetry using a silver cathode in BID-alkaline solution, the current of the peak was proportional to square root of the sweep rate of potential and also proportional to concentration of BID. Activation energy was calculated for 3.75 kcal/mole from the plot of log $I_l$ vs. 1/T. Consequently, the reduction current of BID with a silver cathode in alkaline solution was found the diffusion current.

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Constituents of Flowers of Carthamus tinctorius L. and Their Antioxidant Activity (홍화의 성분 분리 및 항산화 활성)

  • Choi, Hyun-Gyu;Jiang, Yan-Fu;Park, Sung-Hee;Son, Ae-Ryang;Na, Min-Kyun;Lee, Seung-Ho
    • Korean Journal of Pharmacognosy
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    • v.42 no.2
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    • pp.110-116
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    • 2011
  • As part of our ongoing study focused on the discovery of antioxidants from natural products by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, methanol extract of flowers of Carthamus tinctorius L. was found to show potent antioxidant activity. Activity-guided fractionation of the methanol extract lead to the isolation of twenty compounds including two flavonol glycosides, quercertin-3-O-${\beta}$-D-glucopyranoside (12) and kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl-${\beta}$-D-glucopyranoside (18), two flavanone glycosides, (2S)-4',5,6,7-tetrahydroxyflavanone 6-O-${\beta}$-D-glucopyranoside (15) and (2R)-5,7,8',4-tetrahydroxyflavanone 8-O-${\beta}$-D-glucopyranoside (16), and two acetylenic glycosides, 8Z-decaene-4,6-diyne-1-O-${\beta}$-D-glucopyranoside (13) and 4,6-decadiyne-1-O-${\beta}$-D-glucopyranoside (14). Their chemical structures were identified by using spectroscopic analysis. Among them, compounds 12-18 were tested in DPPH assay. Compounds 13-16 were first reported to their antioxidant activity. Quercertin-3-O-${\beta}$-D-glucopyranoside (12) showed the most potent inhibitory effect on DPPH with $IC_{50}$ value of 56.7 ${\mu}M$.

The Stereospecific Synthesis of Abscisic Acid

  • Park, Oee-Sook;Lee, W.Y.;Park, J.C.
    • Korean Journal of Pharmacognosy
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    • v.17 no.1
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    • pp.67-72
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    • 1986
  • A stereospecific synthesis of 3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2,4-pentadienoic acid (abscisic acid) from ${\alpha}-ionone$ has been investigated. Ethyl 5-(2,6,6-trimetyl-2-cyclohexen-1-yl)-trans-4-penten-2-ynoate $({\alpha},{\beta}-acetylenic\;ester)$, which was synthesized from alpha-ionone in two steps, was stereospecifically converted in good yield into ethyl 3-methyl-5-(2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2, 4-pentadienoate $({\alpha}-ionylideneacetate)$ by the conjugate addition of lithium dimethylcuprate at $-78^{\circ}C$. Basic hydrolysis of the ethyl ${\alpha}-ionylideneacetate$ gave an abscisic acid precursor, 3-methyl-5-(2,6,6-trimethyl-2-cyclohexen-1-yl)-cis, trans-2,4-pentadienoic acid, which can be oxidized to yield abscisic acid.

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Synthesis, Spectral Characterization, Electron Microscopic Study and Influence on the Thermal Stability of Phosphorus-containing Dendrimer with a 4,4'-Sulphonyldiphenol at the Core

  • Dadapeer, Echchukattula;Rasheed, Syed;Raju, Chamarthi Naga
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.498-502
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    • 2011
  • The divergent synthesis of novel phosphorus-containing dendrimer with 4,4'-sulphonyldiphenol at the core has been accomplished involving simple condensation reactions using $P(O)Cl_3$, $P(S)Cl_3$, 3-amino-phenol, 3-hydroxy-benzaldehyde, and 2-butyn 1, 4-diol. The final compound was a Schiff's base macromolecule possessing 4 imine bonds, 8 acetylenic bonds and 8 OH groups at the periphery. The structures of intermediate compounds were confirmed by IR, NMR ($^1H$, $^{13}C$ and $^{31}P$), LC-Mass and C, H, N analysis. The structure of the final dendrimer (5) was confirmed by IR, NMR ($^1H$, $^{13}C$ and $^{31}P$), MALDI-TOF-MS, and C, H, N analysis. The surface morphological characteristics of the final dendrimer were understood by Scanning Electronic Microscopic study (SEM). The thermal stability of the final dendrimer was studied by TGA/DTA analysis.

Synthesis and Biological Evaluation of 2-Amino-4H-pyran-3,4,5-tricarboxylate Salt Derivatives

  • Akbari, Ali;Azami-Sardooei, Zabihollah;Hosseini-Nia, Asghar
    • Journal of the Korean Chemical Society
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    • v.57 no.4
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    • pp.455-460
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    • 2013
  • A novel and simple method for the synthesis of 2-amino-4H-pyran-3,4,5-tricarboxylate derivative and the evaluation of their antibacterial activity against Pseudomonas syringae, Xanthomonas citi and Pectobacterium carotovorum are reported. The structure of the isolated compounds has been determined by means of $^1H/^{13}C$ NMR and FT-IR Spectroscopy. The reaction of alkyl isocyanides with acetylenic esters in the presence of dimethyl acetone-1,3-dicarboxylate in the present of $BF_3.SiO_2$ at ambient temperature. Some of the compound showed significant inhibition to growth of bacteria.